Improvement in saw-mills



De W. C. PRESCUTT.

Saw-Milks.

N0.}50,975. APatented Maj/19,1874.

Figi.

UNITED STATES PATENT OFFICE.

DE WITT CLINTON PRESOOTT, OF MARINETTE, WISCONSIN.

IMPROVEMENT IN SAW-MILLS.

Specification forming part of Letters Patent No. 150,975, dated May 19,1874; application filed July 2, 1873. p

OASE B.

To all whom it may conccrn:

Be it known that I, DE WITT CLINTON PEEscoTT, of Marinette, county ofOeonto and State of Wisconsin, have invented certain Improvements inSaw-Mills.

The following description, taken in connection with the accompanyingdrawing hereinafter referred to, forms a full and exact speciiication,wherein are set forth the nature and principles of the invention,together with such parts thereof claimed as new and desired to besecured by Letters Patent of the United States.

My invention consists of a mechanism by which the rake or overhang ofgang or muley saws may be adjusted to the different changes of feedwhich are given to logs in passing through them, and the nature thereofis hereinafter described and shown.

In the accompanying drawing, which illustrates my invention and forms apart of the specification thereof, Figure lis an inside elevation of thevariable saw-rake mechanism. Fig. 2 is a rear view of the same, portionsof shafting being removed, but are supposed to .extend to the oppositeside of gang, to which a similar mechanism is attached. Fig. 3 is anoutside or front elevation of the bracket, having slide-rest, with itsbox, gears, and screw, illustrating the details of the construction ofthe mechanism by which the rake is adjusted.

The construction of my invention is as follows: In the drawing, Adesignates a bracket, with its projecting slide-rest B, which supportsthe sliding box O, with its lug D, in the upper end of which is a femalescrew, for the reception of the male screw E, by which it is operated.The said screw E is supported by a lug or arm O of bracket A, and isretained in position endwise by the collar P and the keyed gear F. Itreceives motion and power from the hand-wheel I by means of t-hc shaft Hand its keyed gear G. K2 isr a link, one end of which is fitted to shaftL, the other being connected to the bottom of the upper slide J, withpin at joint N, to which is imparted the action of the sliding box C,operated by the mechanism aforesaid. v

The operation of the machine is as follows: A log being placed upon thefeed-rollers, and motion given to the gang of saws, and to the flutedfeed-rollers as well, (the same being driven by engine or water-wheel,)the log advances toward the saws; but previous to their entry it becomesnecessary to give them rake3 or, in other words, the top of the sawsmust lcan forward in such manner that a plumb-line suspended at thepoints of the top teeth will indicate the bottom teeth to beconsiderably back of it, thus showing that the saws have an overhangforward, or, as it is termed, rake. This is done to permit the log tofeed when the saws are ascending, and to cause each tooth to do itsproportionate share of the cutting.

To give the saws the required rake, the lower ends of the upper slides Jand J Vare set forward of the perpendicular position they were supposedto occupy, as at Q, Fig. 1, by means of the links K2, shaft L, andsliding boxes O, which are operated by the handwheel I, by means of theshaft H, gears G and F, and screws E. Running in slides J are the boxesIt, which are attached to the upper end of the gate or sash containingthe gang of saws, which, following the direction of slides J, are setforward gradually in their descent,

thus raking the upper ends of the saws toward theV log, giving them, atthe completion of the stroke, the full rake they require.

To adjust the rake of the saws to the feed of the logs, which varieswith their sizes, the lower ends of the slides J are advanced or -drawnback, as the case demands. lThe saws require greater rake for heavy orfast feeding than for light or slow.

Having thus described the construction and operation of my invention, Iwill state what I claim and desire to secure by Letters Patent in thefollowing clause-that is to say, I claim- The variable slides J, thelinks K2, shaft L, brackets A, with their projecting slide-rests B andlugs or arms O, the sliding boxes O, with lugs D, screws E, gears F andG, shaft H, and hand-wheel I, all combined and operating together, asand for the purposes described.

In testimony that I claim thejforegoing I have hereunto set my hand this7th day of May, 1873.

` D. GLINT. PBESGOTT. Witnesses:

GEO. CLARK, Monats B. DODGE.

